How about having the non-stop line go past the circle altogether? Like:

Actually that's just what I did last night. It does curve the Jubilee
more then I'd like, but I have to make some compromises...
Hopefully the updated map will be online tonight.


Yes. this requires a little geographical deviation, but your map is a map
of lines, which are conceptual entities defined by service patterns of
trains, not a map of tracks, which are those long, thin bits of metal.

True! (and I'll save that in my quotes archive ;-)